Can superheroes stop the construction of the Dakota Access Pipeline? We’ll see. “Justice League’’ actors Ben Affleck, Ray Fisher, Gal Gadot, Jason Momoa, and Ezra Miller have taped a public-service announcement endorsing the Rezpect Our Water campaign opposing the pipeline. The Change.org petition, started by members of the Standing Rock Sioux Tribe, opposes a private oil company’s plan to build a pipeline that would cross the Missouri River less than a mile from the Standing Rock Reservation and potentially adversely affect the tribe’s land and water supply. “As a gang of earth defenders, we want to send a big shout out to the Oceti Sakowin and those who stand with them in opposing the Dakota Access Pipeline,’’ Miller said. “Justice League’’ opens in theaters on next year.